How many times must each signal be called by crewmembers?

Each signal must be called by crewmembers three times to ensure clear communication and safety during operations. This practice is crucial in the railroad industry where operations occur in high-pressure environments and clear, unmistakable signals can prevent accidents. By repeating the signal three times, it reinforces the instruction and reduces the chances of misunderstanding or miscommunication among crewmembers. This protocol helps to establish a consistent and reliable communication system, which is vital for coordinating actions and maintaining safety standards on the tracks.